Antistatic photographic film and film base therefor



Oct. 9, 1928. 1,687,042

P. c. SEEL ANTISTATIC PHOTOGRAPHIC FILM AND FILM BASE THEREFOR Filed Aug. 12, 1927 L/ghf sensjfive phofvgm hi0 bye; such as gelafmo-s/jlver-ha in emu/won.

E/CfT/f/O/Q film such as a pyroxy/m layer AMI-#22270 layer con/290mg an ab/ef/c 00/0 esfen Paul GSeeL,

INVEN TOR,

By @XXW A TTORN E Y patented Get. 9, 19289 tlNlTED STATES PATENT OFFICE.

new. c. snnn or BOCHESTER'NEYWYOBK, ASSIGNOB 'ro EASTMAN xormx some,

or noonnsrnn, NEW YORK, A CORPORATION on NEW YORK. I

ANTISTATIG PHOTOGRAPHIC FILM AND FILM BASE THEREFOR.

Application filed August 12, 1927. Serial No. 212,569.

lhis invention relates to antistatic photographic film and to the base or support thereof. One object of the invention is to provide such a film which will have the usual quali-.

ties required to meet 'commercial conditions and will have, in addition, the ability to prevent or greatly lessen defects due to .electrical dischar es-which are customarily referred to as static markings. Other objects will hereinafter appear;

. In the accompanying drawing the single figure is a diagrammatic section, upon an enlarged scale, of a photographic antistatic film embodying my invention.

I have found that a'photographic film in which the light-sensitive photographic layer, such as a gelatino-silver-lialide emulsion, is carried by an electrifiable base or support, can be rendered substantially antistatic by providing it with a layer or backing containing an abietic acid ester. Ehis backing is on the face of the support opposite to the one carrying the emulsion. Only a very thin layer, relative tothe thickness of the support, is required to bring about the antistatic'result. t is, therefore, comparativei inexpensive to carry out my invention.

in the, preferred form of my invention, which will be described in detail by way oil illustratiornl dissolve 3 parts by weight of the abietic acid ester in 97 parts by weight of acetone. The surface of the support to be. coated is then brought very rapidly into and out of contact with this solution, so as to evenly and thoroughly coat it with a very thin layer. The acetone rapidly evaporates,

leaving a sufi'iciently hard backing, and yetthe acetone insures a strong bond between the abietic acid ester coating and the pyroxylin or other electrifiahle film support. 01' course, in place of acetone any other volatile solvent, common to the electrifiablc support and the abietic acid ester, can be employed.

-is available commercially in a form resembling copal. In the thin layers which louse it is substantially colorless, flexible and transparent. Since static manifestations are most apt to occur upon developing motion picture negative film that hasbeen exposed under particularly dry atmospheric conditions, invention is at the present time of most utility in rendering such film antistatic.

Having thus described my invention, what I claim as new and desire to secure by Letters Patent is:

1.; A flexible, photographic .filrn compris ing an'electrifiahle support carrying on one face a light-sensitive photographic coating and on the other face an antistatic layer containing an abietic acid ester.

2. A photographic film comprising a nitrocellulose support carrying on one face gelatino-silver-halide emulsion. and on the other face an antistatic layer containing an abietic acid ester of glycerol.

3. A flexible, transparent base or support adapted to receive light-sensitive photographic coatings, which comprises a main nitrocellulose ayer and a relatively thin coating of an abietic acid ester of glycerol.

Signed at, Rochester, New York, this day of August, 192?.

PAUL C. SEEL.

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